Many electronic devices include a docking station for providing a convenient interface for transferring data between the electronic device and other devices, such as a computers, speakers, monitors, and printers. The docking station may also include an interface for connecting to a power source so that the electronic device can be powered or charged (e.g., battery). In most cases, the docking stations include a cavity within which the electronic device is received. The cavity is configured to have a size and shape that coincides with the size and shape of the electronic device so that the electronic device rests snuggly within the cavity. Furthermore, the cavity typically includes a connector therein for operatively engaging a port of the electronic device when the electronic device is positioned within the cavity. The connector is typically coupled to the external systems (e.g., computer, power source) through a cable so that communications between the electronic device and the external systems can take place.
Recently, inductive charging units have been implemented in electronic devices, the most famous of which is the Sonic Care toothbrush manufactured by Philips of the Netherlands. The toothbrush and the charging dock form the two part transformer with the primary induction coil contained in the dock and the secondary induction coil contained in the toothbrush. When the end of toothbrush is placed in a cavity of the dock, the complete transform is created and the induced current in the secondary coil charges the battery.
Inductive charging pads have also been developed. The pad works similar to the toothbrush, however, the pad typically includes multiple transformers so that the electronic device can be placed in any orientation on the pad. When the electronic device is placed on the pad, one of the transformers of the pad induces current in the transformer of the electronic device, and this current charges the battery of the electronic device. Unfortunately, the efficiency of the transform is not very good since the transformer located on the electronic device typically does not align with the transformers of the pad, i.e., does not create closed magnetic loop and therefore there is no direct inductive coupling.